Variable geometry nozzle systems with adjustable pivot vane configurations require the vanes to be positioned in a nozzle of a compressor, for example. For this purpose, a preassembled variable nozzle cartridge already comprising vanes can be mounted to the compressor of a turbocharger.
One possibility of such a variable nozzle cartridge comprises among other parts two parallel wall members, i.e. a disk insert or diffuser plate and a back plate, between which vanes are disposed. Each vane is pivotally mounted to the back plate by means of a pivot axle of the vane about which the vane can pivot, and by means of a tab member having an elongated head and being integrally provided on the vane. When mounting the vane to the back plate, the pivot axle is stuck into a respective hole of the back plate and the tab member is inserted into a respective assembly slot of the back plate as well as into an actuating slot of a unison ring positioned on the backside of the back plate. The back plate also has guide slots each of which is substantially perpendicular to the associated assembly slot and is in connection therewith such that one guide slot and one assembly slot established a T-shaped slot in the back plate. The guide slots guide shafts of the tab members when the unison ring is rotated relative to the back plate so as to pivot the vanes.
Furthermore, spacers are provided between the back plate and the diffuser plate so as to secure a certain distance there between. The diffuser plate provides a sliding surface for the vanes.
There exists a need for a variable nozzle device having a high performance and a high functionality.